It was the most intense fighting that northern Iraq has seen this year.

In the most intense fighting that northern Iraq has seen this year, at least 180 Islamic State fighters were killed in a U.S.-led assault that began about 4 p.m. Wednesday, reports The Washington Post.

At least four coordinated attacks by more than 300 heavily armed militants kicked off the most intense fighting that northern Iraq has seen this year, illustrating the extremist group’s continued potency despite a year-long air campaign by the United States and its allies. It is an indication of the challenges that Iraqi forces and their U.S. backers will face as they seek to reclaim Mosul and other areas under Islamic State control in Iraq and Syria.

Brig. Gen. Mark Odom, the top U.S. military official in northern Iraq, said that U.S. and allied aircraft launched a 17-hour aerial attack in response to the offensive against Iraqi Kurdish security ­forces, known as the peshmerga.

The Islamic State assault began about 4 p.m. Wednesday and targeted at least four positions along the front line north and east of Mosul that peshmerga fighters have held for months. One site, which was hit by a barrage of artillery fire, was a base used by Turkish troops training local ­forces.

We hope the U.S. and its allies continue to work to wipe out these religious extremists.